diff --git a/lib/web3.js b/lib/web3.js
index b240bdae2..9a85c4d1b 100644
--- a/lib/web3.js
+++ b/lib/web3.js
@@ -505,4 +505,5 @@ function messageHandler(data) {
     }
 }
 
-module.exports = web3;
+if (typeof(module) !== "undefined")
+    module.exports = web3;